This video is of a lecture that Stephen Schneider presented a number of times. It covers climate change from a risk perspective, discussing the underlying science, uncertainties, and implications of different possible decisions. Here is it captured with many (although not all) of his graphics. It is a well organized, evenly presented lecture that carefully differentiates questions of "what we know" from "what we should do." It presents data and modelling at a level appropriate for undergraduates.